thanks for the replies guys.

but, i think you’re missing the most important part. when i try to ‘add’ an external pot, either 10k or 100k, to the existing fader connections with temporary clips attached to the fader points, the pedal SHUTS OFF. as in, bypasses. yes… i have the right spots.

there’s absolutely no problem with me adding in a 3PDT to switch the 3 fader lugs to an external pot, i’ve worked on numerous pedals and added many expression jacks. but, this seems to be different, and i’d like to err on the side of caution given the price of the pedal.

usually before i add an external expression jack (be it switched to replace, or in series with the original pot) i test out the effectiveness by putting the original pot at it’s maximum resistance and adding the secondary pot temporarily to test it out. the signal will, as Ned said, take the least resistive path through the aux pot, given the pinouts and impedance are similar.

this has worked just fine on my microsynth and other pedals.

so, BEFORE i modify the pedal by adding in a 3PDT to route the LPF signal to either the fader or an external jack, i want to make sure the same result with my tests (turning off) will not happen. this leads to the fader… obviously, if it is a standard taper/impedance fader there should be no problem, read it with a meter or just read the value and go from there. oh, no… not that easy. the only marking on the fader is:

“442NA4H103CDN” … google leads to nothing.

meter? sure. measuring the pot value with no power to the unit, it seems to be 420 ohms. at 50% the fader offers up a 2.6K reading. at 75% up, the fader reads 1.1k. every fader on the unit is like this, absolutely identical readings from pin 1 to 3 (total impedance), and mid and 3/4 points. now, given the problem of the unit switching off electronically when testing those pot/fader points, i’m not going to power it up again and start probing, although that might get the answers i need.

in summation, i guess i need a 100% accurate description of the fader pot size and taper, because both the printed number on the side and meter readings don’t mesh with anything i’ve encountered before… or an explanation as to why my unit shuts off when i try to add a secondary pot.

phew!